The applicant proposes to develop a series of non-steroidal androgen receptor agonists which could be used as male contraceptive agents. Three specific aims are proposed. The first is to synthesize 4 chemicals that are analogs of bicalutamide (Casodex) and are stereochemically pure enantiomers. The second is to characterize the androgen receptor binding properties of these compounds and to assess their relative agonist/antagonist activity. The third is to test the biological activity of the best two compounds by treating male mice for 60 days with doses ranging from 0.1 to 50 mg/kg, mating each male to three females, and assessing the drug effects on fertility and quality of progeny outcome.